1. Field of the Invention
This invention relates to an image printing apparatus and a method of controlling the same. More particularly, this invention relates to an image printing apparatus which reads an image original and prints it by using a printhead of inkjet printing method and a control method applied to this apparatus.
2. Description of the Related Art
A so-called multi-function printer (MFP) having an image reading function in addition to a print function is recently widespread, replacing a so-called single-function printer (SFP) having only a print function.
In addition to the single-function printer's “print function” of printing print data generated by a host apparatus such as a personal computer, the multi-function printer has the following functions: a “direct print function” of printing image data stored in, e.g., a memory card without intervening a host apparatus such as a personal computer, an “image supply (scan) function” of supplying image data generated from a read original to, e.g., a personal computer, and a “copy function” of copying a read image without intervening a host apparatus such as a personal computer.
Of these functions, the copy function is unique to the multi-function printer since the function cannot be implemented by a single function apparatus such as a single-function printer or scanner. The copy function includes various copy modes to meet the needs of users.
The copy modes include, e.g., a “same-size copy” mode to copy an original of the same size (magnification rate: 100%) to a printing paper sheet and a “fixed rate magnification/reduction” mode to copy an original with a specific size (e.g., A4 original) to printing paper sheet of a specific size (e.g., B5 paper). There is also a “marginless copy” mode to copy an original on a printing paper sheet without margins.
A multi-function printer having a film reading function also has a “film copy” mode to copy an image read from a transparent original such as a film on a printing paper sheet.
To cope with these various copy modes, the multi-function printer must have an enlargement/reduction function of changing the enlargement/reduction rate to an arbitrary value. Enlargement/reduction processing is executed normally by using a plurality of enlargement/reduction processing units. To control such a plurality of enlargement/reduction processing units, a method disclosed in, e.g., Japanese Patent Publication Laid-Open No. 5-122506 has been proposed.
According to the method proposed in Japanese Patent Publication Laid-Open No. 5-122506, in a system having an enlargement/reduction processing unit on each of the copy original transmitting side and receiving side, if enlargement processing is necessary, the receiving side executes the processing, and if reduction processing is necessary, the transmitting side executes the processing. With this arrangement, the data transfer amount between the transmitting side and the receiving side is reduced, thereby shortening the transfer time and total processing time.
In the above-described prior art, however, if the enlargement/reduction processing units on the transmitting and receiving sides have different processing capabilities, the processing speed lowers under certain processing conditions. Additionally, if different image qualities are obtained by the enlargement/reduction processing units on the transmitting and receiving sides, an obtained copy image may have poor quality under certain processing conditions.
When processible enlargement/reduction rates are determined in the enlargement/reduction processing units on the transmitting and receiving sides, the enlargement/reduction processing itself may be impossible under certain processing conditions.